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M Tzivras

Publications and source records attributed to M Tzivras.

33 records · Page 2Linked to original sources
PubMed1997

Comparative study of artificial neural networks in the discrimination between benign from malignant gastric cells.

OBJECTIVE: To compare the accuracy of two different artificial neural networks (ANNs) for the discrimination of benign and malignant gastric lesions using morphometric and textural data on the nucleus. STUDY DESIGN: Three thousand cells from 30 cancer cases, 26 cases of gastritis and 64 cases of ulcer were selected as a training set, and an additional 10,300 cells from equal cases of cancer, gastritis and ulcer were used as a test set using two different neural net architectures: back propagation (BP) and learning vector quantizer (LVQ). Images of routinely processed gastric smears stained by the Papanicolaou technique were processed by a custom image analysis system. RESULTS: Application of the BP and three variations of the LVQ established correct classification of more than 97% of the benign cells and more than 95% of the malignant cells, obtaining an overall accuracy of more than 97%. CONCLUSION: This study not only presents a comparative study of the abilities of ANNs but also indicates that the use of ANNs and image morphometry may offer useful information on the potential of malignancy of gastric cells.

Adult↗
PubMed1997

One-week therapy with omeprazole, clarithromycin and metronidazole or ornidazole, followed by 3 weeks' treatment with omeprazole, eradicates Helicobacter pylori equally and heals duodenal ulcer.

OBJECTIVE: To estimate and compare the efficacy of 'triple' 1-week regimens--omeprazole, clarithromycin and a nitroimidazole (metronidazole or ornidazole)--followed by omeprazole, for an additional 3 weeks, on Helicobacter pylori eradication and duodenal ulcer (DU) healing, in a country with a high resistance rate of H. pylori to metronidazole. DESIGN: Open, prospective, two-centre study. METHODS: Patients older than 18 years with active duodenal ulcer (DU), diagnosed by endoscopy and found to be infected with H. pylori (modified Giemsa stain and CLO test, Delta West, Australia), were included in the study. Three triple-drug regimens, given for 7 days, were used. (1) omeprazole (Om) 20 mg once a day, plus clarithromycin (Cl) 250 mg twice daily, plus ornidazole (Or) 500 mg twice daily (O1COr); (2) Om 20 mg twice daily, plus Cl 250 mg twice daily, plus Or 500 mg twice daily (OCOr); and (3) Om 20 mg twice daily, plus Cl 250 mg twice daily, plus metronidazole (M) 500 mg twice daily (OCM). Two hundred and three consecutive H. pylori-positive patients were included in the study, randomly assigned as follows: 50 patients (group A1: 32 men, 18 women, age 23-77 years) on O1COr; 47 patients (group A2: 29 men, 18 women, age 27-77 years) on OCOr; and 106 (group B: 71 men, 35 women, age 18-83 years) on OCM. Ulcer healing and H. pylori eradication were assessed endoscopically, 8-9 weeks after the start of treatment. H. pylori was considered eradicated if both histology and rapid urease test (six biopsies, antrum-body) were negative. RESULTS: Eleven patients were lost to follow-up; 192 patients were analysed. Group A1: 48; group A2: 44; group B: 100. 'Per-protocol' analysis: H. pylori eradication, 90-93% (P = 0.901); ulcer healing, 90-98% (P = 0.300). 'Intention to treat' analysis: H. pylori eradication, 85-88% (P = 0.887); ulcer healing, 86-91% (P = 0.657). Compliance was excellent, no serious side effects were observed and no patients withdrew due to side effects. CONCLUSIONS: No differences were observed in the H. pylori eradication and the healing rate among the groups. It seems that twice daily omeprazole is no better than single daily dosage and that ornidazole is as effective as metronidazole. In addition, in the studied population which is believed to have a high prevalence of metronidazole resistance, all the regimens used were effective.

Adolescent↗
PubMed1996

Potential of the back propagation neural network in the discrimination of benign from malignant gastric cells.

OBJECTIVE: To investigate the potential value of morphometry and the back propagation neural network for the discrimination of benign and malignant gastric lesions. STUDY DESIGN: The study group consisted of 23 cases of cancer, 19 of gastritis and 58 of ulcer. Images of routinely processed gastric smears stained by the Papanicolaou technique were processed by a custom image analysis system. Analysis of the images gave a data set of 11,024 cells. Two different neural net architectures were used to classify benign from malignant cells based on the extracted morphometric and textural features. The data from 2,500 randomly selected cells were used as a training set, and the data from the remaining 8,524 cells were applied as a test set. RESULTS: Application of the back propagation neural network permitted the correct classification of 97.6% of benign cells and 95% of malignant cells with overall accuracy 97.3%. CONCLUSION: These results indicate that neural networks and image morphometry may offer useful information about the potential for malignancy in gastric cells.

Adult↗
PubMed1996

Gastric epithelial polyps: a retrospective endoscopic study of 12974 symptomatic patients.

This is a retrospective endoscopic study on the incidence of gastric epithelial polyps (adenomas, hyperplastic, inflammatory) in 12,974 consecutive symptomatic Greek adults submitted to endoscopy during a 4-year period, in two endoscopy units. A total of 258 polyps were found in 157 patients (1.2%), 80 males and 77 females (age: 22-87 years); 67.5% of these patients were older than 60 years. Two hundred and two (202) polyps were totally removed. In 43 patients (27%), more than one polyp was found. Polyps were mainly hyperplastic (75.6%). Adenomas were found in 6.6%, and only in patients older than 50 years. Hyperplastic and inflammatory polyps were equally distributed in males and females. A male predominance was observed in adenomas (2:1). Most of the polyps were in the antrum (43.8%) and were hyperplastic (75.2%). Of 501 previously operated patients (gastrectomy or gastrojejunostomy), 26 (5.2%) had polyps. No adenomas were seen in the anastomosis area. Most of the polyps (61.9%) were smaller than 0.5 cm; 13.3% were greater than 1 cm. No coincidence of polyps with gastric cancer was observed.

Adenoma↗
PubMed1992

Ranitidine and antacids in the prevention of duodenal ulcer relapse in Greece.

The present study was undertaken to compare the efficacy of ranitidine 150 mg/nocte with that of antacids taken "on demand" in the prevention of recurrence of duodenal ulcer (DU). Two groups (A, B) of patients with DU recently healed by ranitidine or antacids were studied. Patients of Group A (110) healed by ranitidine were put on maintenance treatment with ranitide, and patients of Group B (32) healed by antacids were given antacids "on demand" for a period of one year. Endoscopy was performed at the end of the 6th and 12th months, as well as whenever symptoms appeared. Patients were followed up clinically at 2-month intervals. Relapse rates of 11% (group A) and 34% (group B) were found at the end of the 6th month, (p less than 0.005), while the total relapse rates at the end of the 12th month were 19% and 47%, respectively (p less than 0.005). Recurrences were asymptomatic in 62% (Group A) and 27% (Group B) of patients. No significant side effects were observed. It is concluded that ranitidine 150 mg nocte is significantly superior to antacids "on demand" as far as the recurrence of DU is concerned.

Adult↗
PubMedDate not supplied

H3 Propranolol serum levels following lidocaine administration in rats with CCL4 induced liver damage.

Liver disease alters the pharmacokinetic and pharmacodynamic properties of hepatically eliminated drugs. The main factors influenced are plasma albumin levels, enzyme balance (induction & inhibition) and drug binding to tissue proteins. The influence of lidocaine on serum, heart and liver propranolol levels in Wistar rats after liver injury induced by carbon tetrachloride CCl4 0.4 ml/kg x 2/wkl, was investigated. 40 male Wistar rats were divided into four groups (I, II, III, IV; n=10), Group I animals received only propranolol (labelled + cold substance) 40 mg/kg/12 h p.o., group II propranolol plus lidocaine in a single dose of 4mg/kg s.c., group III was treated with CCl4 for 6 weeks and received propranolol x2 at the same dosage as group I, while group VI was treated with CCl4 and the same drug dosage as group II. The simultaneous administration of H3-propranolol and lidocaine increased propranolol levels in the serum and tissues. The liver in damaged animals showed an increase of propranolol level under lidocaine co-administration, probably due to CCl4 induced liver enzyme activity, resulting in a rapid propranolol metabolism or to competition between both drug protein binding sites. The increased propranolol levels in the heart after lidocaine administration were probably due to attributed to its high affinity for heart tissue. Consequently, as regards the therapeutic approach for patients with liver disease receiving propranolol their propranolol dosage should be reduced when lidocaine is co-administered.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

High eradication rate of Helicobacter pylori using a four-drug regimen in patients previously treated unsuccessfully.

The objective of this study was to assess the efficacy of a new regimen in eradicating Helicobacter pylori (Hp) in patients with duodenal ulcer (DU) who were previously treated unsuccessfully with standard triple therapy (tripotassium dicitratobismuthate [TDB] 120 mg QID, metronidazole 500 mg TID, and tetracycline 500 mg QID) or proton-pump inhibitor (PPI) dual therapy (omeprazole 20 mg BID and amoxicillin 500 mg QID). The study included 133 consecutive patients aged 17 to 83 years with endoscopically diagnosed DU (diameter > or = 5 mm) in whom standard triple therapy or PPI dual therapy had failed to eradicate Hp. A rapid urease (CLO) test was performed on four biopsy specimens at study entry and at least 1 month after the end of treatment to confirm Hp colonization and eradication, respectively. Patients were considered to be Hp positive if any CLO test was positive within 2 hours, and Hp was considered to be eradicated if all CLO tests were still negative after 24 hours. In 31 randomly selected patients, Hp eradication was confirmed histologically as well. Patients were given omeprazole 60 mg/d (20 mg in the morning and 40 mg in the evening) plus amoxicillin 500 mg QID for 10 days and subsequently were given metronidazole 500 mg TID for 10 days plus TDB 120 mg QID for 6 weeks. One hundred and twenty-four patients were followed up; five (4%) withdrew because of side effects (protracted diarrhea, stomatitis, skin rashes). Per-protocol analysis showed Hp eradication in 113 of 119 patients (95%) and ulcer healing in 118 of 119 (99%). Intent-to-treat analysis showed an Hp eradication rate of 85% (113 of 133 patients) and an ulcer healing rate of 89% (118 of 133 patients). In per-therapy analysis, the Hp eradication rate was 91% (113 of 124 patients), and the ulcer healing rate was 95% (118 of 124 patients). Side effects were observed in 39 of 119 patients (33%) and were generally mild. The four-drug regimen used in this study, when given to patients previously treated unsuccessfully with standard triple therapy or PPI dual therapy, was highly effective in eradicating Hp and healing DUs and had no major side effects.

Adolescent↗
PubMedDate not supplied

Preliminary evaluation of the potential prognostic value of serum levels of immunoglobulins (IgA, IgM, IgG, IgE) in patients with gastric cancer.

Sixty patients with advanced gastric carcinoma who refused to receive cytotoxic chemotherapy were examined for serum immunoglobulin levels (IgG, IgM, IgA, IgE). Three samples were obtained every two months thereafter. The group of patients who had above-normal values of one or more of the examined immunoglobulins had a longer survival than the other (p < 0.024). Immunoglobulin values were independent of the Helicobacter pylori antibody titer and of acute phase reactants. It is concluded that survival potentially correlates with serum immunoglobulin levels. Further studies including larger numbers of patients and correlating serum immunoglobulin levels with specific clinical parameters are needed to establish the prognostic role of serum immunoglobulins in patients with gastric carcinoma.

Adult↗
PubMedDate not supplied

Diazepam treatment in rats induces changes in the concentrations of different phospholipid classes in liver and liver mitochondria.

Liver phospholipid concentrations were determined in rats after the administration of diazepam (5 mg/Kg/day), for a period of two months. Increased concentrations of total phospholipids (P < 0.05), phosphatidylcholine (P < 0.05) and phosphatidylinositol (P < 0.05) were found in the rats taking diazepam. In contrast, a decreased concentration of phosphatidylserine (P < 0.01) was observed in the same group of animals. In addition, changes in the concentration of rat liver mitochondrial phospholipids after the administration of diazepam during the same period of time were determined. Increased concentrations of total phospholipids (P < 0.01), phosphatidylcholine (P < 0.001) and diphosphatidylglycerol (P < 0.001) were found in the rats treated with diazepam. In contrast, decreased phosphatidylserine (P < 0.001) and phosphatidylinositol (P < 0.01) concentrations were observed in the same group of animals. The considerable changes observed in liver phospholipids and individual classes of liver mitochondrial phospholipids induced by long-term administration of diazepam, possibly suggest a stimulation of liver phospholipid biosynthesis. This effect may be related to enzymatic systems which are involved in phospholipid pathways, and are linked to benzodiazepinergic binding sites.

Administration, Oral↗
PubMedDate not supplied

Cisapride, metoclopramide, and ranitidine in the treatment of severe nonulcer dyspepsia.

Cisapride, a prokinetic drug with a novel mechanism of action, was compared with another prokinetic drug, metoclopramide, and an H2-blocker, ranitidine, in the treatment of nonulcer dyspepsia. In a double-blind study, 60 patients with severe dyspeptic symptoms received cisapride 5 mg TID, metoclopramide 10 mg TID, or ranitidine 150 mg BID for 8 weeks. Symptoms were evaluated during treatment and 4 weeks after the end of therapy. All three drugs effectively controlled the symptoms of chronic functional upper gastrointestinal tract disorders. The prokinetic drugs, particularly cisapride, were significantly better than ranitidine in controlling symptoms, especially reflux symptoms. All three drugs were generally well tolerated; cisapride in particular was associated with fewer adverse effects.

Adult↗